In recent decades, minimization and recycling/reuse policies were introduced to reduce the quantities of generated waste and for alternative waste recovery. Organic wastes represent 46% of total global solid waste. Possible uses of organic wastes include using it as fertilizer and amendment for soil, for energy recovery and for the production of chemical substances. Sewage sludge disposal and reuse are identified as future problems concerning waste. The total amount of sludge generated in the entire world has increased dramatically, and this tendency is expected to increase significantly in the years to come. In most developed countries, special attention is given to sewage sludge treatment in order to improve the quality and safety of using it on the ground surface. Sewage sludge pyrolysis is considered an acceptable method, from an economic and ecological perspective, for the beneficial reuse of sewage sludge. This method has many advantages because, during the pyrolysis process, the sludge volume is reduced by 80%, pathogenic agents and hazardous compounds from sewage sludge are eliminated, metals are immobilized in solid residue and organic and inorganic fractions are immobilized in a stabilized form of pyrolytic residues (biochar). The biochar generated by sewage sludge pyrolysis does not contain pathogenic agents and is rich in carbon and nutrients.

In the field of purification and treatment of waste water resulting from various domestic and industrial activities, classical methods of retention of pollutants almost can no longer eliminate their large quantities, and this signifies a problem related to the environment. Filtration membrane technology has a larger footprint in the removal of these pollutants, and their success is due to virtually the quality of the resulting water. This paper highlights the development of a wastewater ultrafiltration process, containing bentonite, an inorganic compound found in wastewater from industries such as the steel industry, food industry, and so on. This study aims to find the relation between all parameters present in the ultrafiltration process, respectively how these parameters can influence each other. The study is necessary because bentonite, from a common substance, can be a dangerous pollutant, especially if it comes into contact with other compounds that in chemical reactions can harm the environment, and this raises questions to researchers who are experimenting with water purification technologies at a state-of-the-art level. At the same time, the study aims at determining the percentage of bentonite retaining on the membrane filtration surface, and in the final analysis of how bentonite can block the pores of the membrane or deposit on its surface. Throughout the entire ultrafiltration experiment it will be monitorized parameters related to organic membrane with hollow fibers and the results of physico-chemical indicators obtained at the final of the process. The results of the study showed that bentonite can be retained more than 20%. Accumulation of bentonite on the surface of the membrane decreased slightly the volume of permeate at the end of the experiment, resulting in an insignificant decrease in the volume of the liquid in the membrane. The results on bentonite retention efficiency and dependence parameters in the ultrafiltration process will be detailed in the present paper.

<p>The water deficit for consumption in various daily activities is more pronounced especially in countries where rainfall is low or in those areas where water demand is higher than available resources. This paper is a comparison between the airgap and water-gap distillation method. The results of the study have shown that the water-based distillation method can be more efficient, as the volume of permeate obtained is higher in relation to the increase in the flow temperature.The results obtained as well as the comparison of the advantages related to the two membrane distillation processes will be presented in the present paper.<strong></strong></p>

Organic waste management is an important concern for both industries and communities. Proper management is crucial for various reasons, such as reducing greenhouse gas emissions, promoting sustainability, and improving public health. Composted manure is a valuable source of nutrients and organic matter that can be used as a soil amendment in agriculture. Some important benefits of using composted manure in agriculture include: improves soil fertility, enhances soil structure, reduces soil erosion, suppresses plant diseases, and reduces reliance on synthetic fertilizers. Composted manure represents one of the most effective methods of organic waste valorization. Its macronutrients and micronutrients content can increase plant yield, without any reported negative or toxic effects on the soil and plants at various application rates. However, improper use of farmyard manure can have negative effects on the environment, such as air pollution from greenhouse gas emissions, soil acidification, and contamination of surface water and groundwater by nitrates and phosphates. The properties of the soil, including aeration, density, porosity, pH, water retention capacity, etc., can be improved by the structure and composition of manure. The slow-release source of nutrients provided by the nutrient content of compost can determine proper plants growth. However, it is crucial to use compost in moderation and regularly test soil to prevent excessive nutrient application, which can have adverse effects on plants and the environment.

Alpha-cypermethrin is a synthetic pyrethroid that was extensively used for insect control, since the early 1980s. However, it is known that its presence in the environment has toxic effects on humans and aquatic life forms. For this reason, it is commendable for it to be removed completely from the contaminated environment. In this study, we evaluated the adsorption capacity of a marine alga for the removal of cypermethrin from water. The adsorption experiments were performed based on the batch equilibrium technique. The samples containing the pesticide were analyzed using gas chromatography with an electron capture detector, after liquid-liquid extraction in hexane. The results obtained from the kinetic adsorption studies showed that the equilibrium time was attained after 40 min. The adsorption parameters at equilibrium concentrations, obtained through the Langmuir, Freundlich, and Temkin models, showed that the used brown marine alga has a maximum amount of adsorbed cypermethrin of 588.24 µg/g. The correlation coefficients obtained for each model prove that the Langmuir model best fits the experimental data.